Tissues Flashcards
What is a tissue?
a group of cells that are similar in structure and perform a common/related function
What are the four main types of tissues?
- epithelial tissue - ie. skin
- connective tissue - ie. blood, bone, adipose
- muscular tissue - ie. skeletal, smooth, cardiac
- nervous tissue - ie. brain
What is the main function of epithelial tissue?
to form a boundary between different environments and it decides what gets through the boundaries
What are the two types of epithelial tissue?
type 1 - covering/lining
type 2 - glandular
What are the 4 different functions of epithelial tissues? + examples
(i) Physical protections
- stops harmful things from coming inside
ie. skin and bladder
(ii) absorption
- forms selective barriers
ie. small intestine
(iii) sensation
- forms special sensory receptors
ie. taste buds, respiratory
(iv) secretion
- using other glands to make a certain substance
type 1: endocrine = make products directly into the bloodstream
ie. thyroid, pituitary and pancreas
type 2: exocrine = make products in ducts to specific areas
ie. sweat, earwax and saliva
What does the basic structure of the epithelial tissue include?
- apical surface = surface that is exposed to exterior environments, often having microvilli or cilia
- basal surface = anchored lower surface
- basal lamina = sheet beneath the basal surface, joins the connective tissue to the epithelial tissue
- basement membrane = dense, a sheet made of the basal lamina and reticular lamina which includes an extracellular matrix and separates the tissues
What is avascular?
meaning the blood vessels, arteries and veins DO NOT go directly into them, they get their energy from nearby blood vessels
What are the classifications of epithelial tissue?
(i) arrangement of layers
(ii) cell shape
What are the types of arrangements of layers of epithelial tissue?
- simple = single layers stacked
- pseudostratified = every cell contacts base layers
- stratified = multiple layers stacked
What are the types of arrangements of shapes of epithelial tissue?
- squamous = thin, flat and wide
- cuboidal = cube shape
- columnar = tall, thin and rectangular
What are the “rules of thumb” when it comes to classifying epithelial tissue?
- more layers = more protection (stratified)
- single layers = it’s easier for substances to pass through
- cilia will help movement and sensations
What are the three classifications of simple epithelial tissue?
- simple squamous epithelium
- thin layer
- allows molecules to pass through
- good for absorption and secretion
ie. gas exchange
- simple cuboidal epithelium
- good for passing of fluids
- absorption of fluids
ie. kidney
- simple columnar epithelium
- helps with movement and absorption
(i) non-ciliated
- there are microvilli
- a single layer of columnar cells
ie. small intestine
(ii) cilia
- covered in cilia on the apical surface
ie. fallopian tubes
What are the three classifications of stratified epithelial tissue?
- stratified squamous epithelium
- multiple layers
- squamous at the top layer
- The bottom layers have nuclei, and the top layers do not
ie. vagina
- stratifed cuboidal
- layered
- not as protective
- they do not overlap
ie. esophagus
- stratified columnar
- less layers
ie. urethra, front layers of the eyeball
What are the two classifications of pseudostratified epithelial tissue?
- pseudostratified ciliated columnar
- appear to be in layers but are not
- each cell hits the basement membrane
ie. epithelium in the trachea
- transitional
- stratified layer of cells that change shape based on where they are and what loads are on them
ie. bladder
What is connective tissues’ overall role?
support!!
What are all types of connective tissue made of?
mesenchyme
What are the 4 types of connective tissues?
- Connective tissue proper
- Cartilage
- Bone
- Blood
What are the 6 functions of connective tissue? + examples
- supporting
ie. bone, cartilage - binding
ie. tendons bind muscles to bones - storage (reverse fuel)
ie. Adipose is a connective tissue that stores energy - Transporting substances
ie. Blood can transport nutrients - Protection
ie. skeleton and “fat pads” in the heels - immune protection
ie. white blood cells are made in the marrow that can fight off unwanted pathogens
What are the three structural elements of connective tissue (all 4 types have the same 3 structures)
- cells = living
- defence cells (breakdown invaders)
- fibroblasts make fibres and ground substance
- adipose cells (aka adipocytes): contain lipids, energy storage, cushion/protect some hormones
ie. macrophages, fibroblasts, mast cells, plasma cells, neutrophils, eosinophils and adipocytes
- ground substance = nonliving
- thick fluid component - fibers = nonliving
- elastic: yellow, allows for stretch and recoil, elastin protein
- reticular: white, tough but flexible, branching/lattice network, collagen portein
- collagen: white, strong, flexible, resistant to stretch, collagen protein
True or False
Ground substance + fibres = extracellular matrix (non-living components)
true
What are the two types of connective tissue proper?
type 1: loose
type 2: dense
what are the subtypes of the CT proper loose? and where are they found?
- areolar
- least specialized type
- lots of cell combos aka lots of structures
- found in the skin, lining of capillaries - adipose
- mostly adipocytes
- contain lipids
- found in the female breast, and around some organs for protection - reticular
- most reticular fibres
- form supporting frameworks
- found in liver, spleen, lymph nodes
What are the subtypes of the CT proper dense? and where are they found?
- regular
- lots of aligned collagen fibres (strong in one direction)
- found in ligaments and tendons - irregular
- collagen fibres in mesh patterns
- multi-directional
- found in skin, lining around bone/cartilage - elastic
- collagen and elastic fibres, stretch and recoil
- found in arteries, ligamentum flava
what is cartilage?
- chondrocyte: developed from chondroblasts, produce collagen, elastic fibres, ground substance (like fibroblasts)
- the chondroitin sulfate in cartilage ground substance, gives resilience so it can take a greater force
- perichondrium is a dense layer of CT covering cartilage
What are the types of cartilage?
type 1- hyaline: most common
- high concentration of collagen fibres
- found at ends of bone
- in between ribs and sternum
type 2 - elastic: most elastic/flexible
- made of both collagen and elastic fibres
- has outer perichondrium
type 3 - fibrocartilage: strongest most resilient
- made of chondrocytes and collagen fibres arranged in parallel rows
- shock absorption
- no perichondrium
What are the two types of bones?
- compact: harder than spongy
- spongy: where things are stored (marrow)
What is the role of bones and examples of them?
- biggest role is support
- also protects
- houses blood-forming cells
- relatively tough and only has collagen and calcium
What is the role of blood and what examples of them?
- main function is transporting to support tissue (transporting oxygen)
- has plasma and cells (red, white and platelets)
What are the four subgroups in the blood?
- red blood cells
- white blood cells
- platelets
- plasma
What makes up membranes?
epithelia + connective tissue + basement membrane
What are the four types of membranes?
- skin: aka cutaneous membrane
made up of - epithelia + dermis (CT) - mucous
made up of - epithelia + loose CT
- lines inside or organs like respiratory, urinary, digestive, reproductive - serous
made up of - simple epithelia + loose CT
- produces thin watery fluid
- found in lungs and heart - synovial
made up of Synovial cells + loose CT
- tech NOT epithelial membrane
- lines synovial joint cavities, makes synovial fluid
